Air-compressor for air-brakes.



' Paitentod mv. 1902.

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UNITE STATES PATENT OFFICE.

BURT J. DENMAN,

OF TOLEDO, OHIO, ASSIGNOR TO JOHN R. B. RANSOM,

' OF TOLEDO, OHIO.

AIR-COMPRESSOR FOR AIR-BRAKES.

SPECIFICATIONforming part of Letters Patent, No. 712,508, dated November 4, 1902. Application filed November 7, 1901. Serial No- 8l,384- (No modeLl To all whom it may concern.-

use the same, reference being had to the ac-- companying drawings, and to the figures of reference marked thereon, which form a part of this specification.

My invention relates to an air-compressor for air-brakes; and its object is to provide an apparatus in which the momentum of a car,

such as an electrically-propelled street-car, shall furnish the energy for compressing the air and in which the air-compressing devices shall be throwninto and out of gear and controlled by electricity.

cured to the truck of the car and in which re- Thefurther objectof my invention is to provide an apparatus which shall be cheap, simple,.anddurable and which shall be controllable by the mere-touch of the operator.

I attain these objects by means of the devices and arrangement of parts. hereinafter described and shown, andillustrated in the accom pan yin g1 drawin gs, in" which- Figure 1 is a side elevation of my device, showing the air-compressor cylinder, the piston, and the air-valves in central vertical section; andFig. 2, a horizontal sectional plan view taken on line w m, Fig. 1.

Like numerals of reference indicate like parts in both views. 3

In the drawings, 1 is a car-axle, upon which runs loosely a cam 2, having a cam-strap 3.

4 is an air-compressor cylinder suitably seciprocates a pistono. The cylinder and piston are of the trunk type. r

6 is a connecting-rod pivotally connected at one end with the wrist-pin Win the piston and connected at its other end with the camstrap.

The working chamber of the air-cylinder is connected with an air-passage 8, in which is an induction-valve 9 and an eduction-valve 10. As will be seen from the drawings, the arrangement of these valvesis such that with the suction-stroke of the compressor the induction-valve is automatically opened and that with the compression-stroke it is closed, while the eduction valve is automatically closed during the suction-stroke and opened during the compression-stroke. The air-passage 8 leads to a receiver for the storage of compressed air, (not shown in the drawings) where the compressed air is stored for use in actuating the brakes, as may be required.

Fixed upon the axle at the side of the cam is a soft-iron disk 11. In the side of this disk next to the cam is a deep concentric channel, in which is secured a coil of wire 12.- On the opposite side of the disk 11 is secured a colsulating-ring l4 and electrically connected, as at 15, with the coil 12. 16 is a brush bearing upon the collecting-ring, which brush is electrically connected with a suitable source of electrical energy. The terminal of the coil is grounded through the wheel of the car and the track-rail. My device is also supplied with means (indicated at 17) disposedwithin convenient reach of the operator tor opening and closing the circuit through the coil 12. In practice there is included in this circuit an automatic make-and-break device, which is controlled by the'variations of air-pressu re in the compressed-air-storage chamber.

The operation of my device is as follows:

is desired to supply compressed air for the operation of the brakes. The circuit through the coil 12 is closed by-the operator, the disk 11 instantly becomes a powerful electromag net, and the two adjoining faces of the cam and the disk are attracted to each other and cling together so closely that the cam revolves with the electromagnetic disk. The camstrap and connecting-rod now communicate motion to the piston in the air-compressor and air is rapidly compressed for useas may be required. Upon breaking the circuit the magnetic disk lets go its hold upon the cam, which now ceases to revolve and stands idle until the circuit is again closed.

Having described my invention, what I lecting-ring 13, insulated from the disk by in- Assume ihat the car is in motion and that it claim, and desire to secure by Letters Patent, 1s

1. In an air-compressor, the combination of an axle, a cam loosely mounted upon said axle and provided with a cam-strap, a cylinder, a piston connected to said cam-strap, an electromagnetic disk fixed upon the axle and adapted for direct engagement with the loosely-mounted cam, and means for controlling the electric circuit in said disk to cause it to directly engage or disengage said cam.

2. In combination, an air-compressor, an axle, a cam loosely mounted upon the axle, a cam-strap in engagement with said cam and connected to the air-compressor, a disk fixedly mounted upon said axle contiguous to the loose cam, an electric coil carried by said disk, a collecting-ring mounted upon and insulated from the disk, connections between the collecting-ring and the coil, and a make-andbreak device in circuit with said coil for controlling the electric circuit in said coil.

3. In an air-compressor for air-brakes, the combination of an axle, a cam loosely mounted upon the axle, a cam-strap in operative engagemennwith the loose cam, a cylinder provided with induction and eduction valves, a piston in said cylinder and connected to the cam-strap, an electromagnet fixedly mounted upon the same axle on which the cam is loosely sustained and means for energizing said electromag-net directly into operative engagement with the cam.

4:. In an air-compressor, the combination of an axle,a cam loosely mounted upon said axle, a cylinder, a piston therein, and operative connections between the piston and loose cam, and means for clutching and nnclutching said cam to and from the said shaft, said means comprising an electromagnetic disk fixed upon the axle contiguous to the loose cam and adapted for direct engagement therewith, an electric coil for said disk and a make-andbreak device for controlling the circuit through said coil.

In testimony whereof I affix my signature in presence of two witnesses.

BURT J. DENMAN.

Witnesses:

M. D. MERRIOK, L. E. BROWN. 

